Transparent articles comprising transparent, nonmetallic substrate and a
transparent film stack is sputter deposited on the substrate. The film
stack is characterized by including at least one infrared reflective
metal film, a dielectric film over the metal film, and a protective
silicon nitride film of 10 .ANG. to 150 .ANG. in thickness over the said
dielectric film. The dielectric film desirably has substantially the same
index of refraction as does silicon nitride and is contiguous with the
silicon nitride film.